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Energy, Énergie, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Installations de production et de conversion d'énergie: énergie électrique, énergie thermique., Installations for energy generation and conversion: thermal and electrical energy., Centrales nucléaires à fission, and Fission nuclear power plants

Cerium dioxide, a non-radioactive surrogate of uranium dioxide, is useful for simulating the radiation responses of uranium dioxide and mixed oxide fuel (MOX). Controlled additions of lanthanum can also be used to form various levels of lattice oxide or anion vacancies. In previous transmission electron microscopy (TEM) experimental studies, the growth rate of dislocation loops in irradiated lanthanum doped ceria was reported to vary with lanthanum concentration. This work reports findings of the evolution mechanisms of the dislocation loops in cerium oxide with and without lanthanum dopants based on a combination of molecular statics and molecular dynamics simulations. These dislocation loops are found to be b = 1/3〈111〉 interstitial type Frank loops. Calculations of the defect energy profiles of the dislocation loops with different structural configurations and radii reveal the basis for preference of nucleation as well as the driving force of growth. Frenkel pair evolution simulations and displacement cascade overlaps simulations were conducted for a variety of lanthanum doping conditions. The nucleation and growth processes of the Frank loop were found to be controlled by the mobility of cation interstitials, which is significantly influenced by the lanthanum doping concentration. Competition mechanisms coupled with the mobility of cation point defects were discovered, and can be used to explain the lanthanum effects observed in experiments.

Energy, Énergie, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Installations de production et de conversion d'énergie: énergie électrique, énergie thermique., Installations for energy generation and conversion: thermal and electrical energy., Centrales nucléaires à fission, and Fission nuclear power plants

The effect of variation in thermal conductivity of light water reactor fuel elements on core response during loss-of-coolant accident scenarios is examined. Initially, a simplified numerical analysis is utilized to determine the time scales associated with dissipation of stored energy from the fuel into the coolant once the fission reaction is stopped. The analysis is then followed by full reactor system thermal-hydraulics analysis of a typical boiling and pressurized water reactor subjected to a large break loss-of-coolant accident scenario using the TRACE code. Accordingly, sensitivity analyses to examine the effect of an increase in fuel thermal conductivity, up to 500%, on fuel temperature evolution during these transients are performed. Given the major differences in thermal-hydraulics design aspects of boiling and pressurized water reactors, different fuel and temperature responses during the simulated loss-of-coolant transients are observed.

Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Surfaces et interfaces; couches minces et trichites (structure et propriétés non électroniques), Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties), Structure et morphologie de couches minces, Thin film structure and morphology, Structure et morphologie; épaisseur, Structure and morphology; thickness, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Structure électronique et propriétés électriques des surfaces, interfaces, couches minces et structures de basse dimensionnalité, Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures, Propriétés électriques de couches minces particulières, Electrical properties of specific thin films, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Méthodes de dépôt de films et de revêtements; croissance de films et épitaxie, Methods of deposition of films and coatings; film growth and epitaxy, Depôt par pulvérisation cathodique, Deposition by sputtering, Sciences appliquees, Applied sciences, Energie, Energy, Energie naturelle, Natural energy, Energie solaire, Solar energy, Conversion photovoltaïque, Photovoltaic conversion, Cellules solaires. Cellules photoélectrochimiques, Solar cells. Photoelectrochemical cells, Analyse structurale, Structural analysis, Análisis estructural, Cellule solaire, Solar cells, Conductivité électrique, Electrical conductivity, Couche mince, Thin films, Couche oxyde, Oxide layer, Capa óxido, Diffraction RX, XRD, Dépôt physique phase vapeur, Physical vapor deposition, Dépôt pulvérisation, Sputter deposition, Microscopie force atomique, Atomic force microscopy, Oxyde d'indium, Indium oxide, Indio óxido, Profilométrie, Profilometry, Perfilometría, Pulvérisation cathodique, Cathode sputtering, Pulvérisation irradiation, Sputtering, Spectre UV visible, Ultraviolet visible spectrum, Espectro UV visible, Traitement thermique, Heat treatments, Verre, Glass, 6855J, 8115C, 8460J, In2O3, Substrat verre, Indium oxide thin films, Low temperature sputtering, Powder target sputtering, and Pulsed d.c magnetron sputtering

Transparent conductive oxide layers are widely used in various applications such as solar cells, touch screen displays, heatable glasses, etc. This present work describes the deposition of transparent and conducting In2O3 films from In2O3 powdered targets using a pulsed d.c magnetron sputtering technique without additional substrate heating or substrate biasing. The films deposited at various oxygen concentrations were approximately 500 nm thick, were pin-hole free and well adhered to the glass substrates. The material characteristics of the films were analysed using X-ray diffraction, four point probe, hot probe, UV-vis spectroscopy, atomic force microscopy and profilometry. Structural and electrical analyses revealed that the films were crystalline and highly conductive when sputtered in the absence of oxygen but a dramatic change in resistivity was observed when oxygen was introduced during the deposition. Resistivity increased from 0.004 Ω cm (no oxygen) to 5 Ω cm with 10% oxygen.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie naturelle, Natural energy, Energie solaire, Solar energy, Conversion photovoltaïque, Photovoltaic conversion, Cellules solaires. Cellules photoélectrochimiques, Solar cells. Photoelectrochemical cells, Bande interdite, Energy gap, Banda prohibida, Caractéristique courant tension, Voltage current curve, Característica corriente tensión, Cellule solaire à colorant, Dye-sensitized solar cell, Célula solar sensibilizada tinte, Composition phase, Phase composition, Composición fase, Dispositif photovoltaïque, Photovoltaic cell, Dispositivo fotovoltaico, Microstructure, Microestructura, Nanoparticule, Nanoparticle, Nanopartícula, Oxyde de titane, Titanium oxide, Titanio óxido, Photoconductivité, Photoconductivity, Fotoconductividad, Semiconducteur, Semiconductor materials, Semiconductor(material), Synthèse chimique, Chemical synthesis, Síntesis química, Synthèse nanomatériau, Nanomaterial synthesis, Síntesis nanomaterial, Traitement thermique, Heat treatment, Tratamiento térmico, DSSC, N719, device fabrication, low band gap semiconductor, mixed phase TiO2, and photovoltaic device

The present work focuses on the synthesis of mixed phase TiO2 nanoparticles with reduced band gaps without even being doped. The synthesis was carried out by chemical route followed by heat treatments at different temperatures to favor rutile incorporation in anatase network. The significance of different heat treatment temperatures on the phase composition of TiO2 nanoparticles and its effect on optical band gap and the photovoltaic performance are analyzed. The thermal analysis, phases, morphology, and energy band gap of as-synthesized TiO2 nanoparticles have been characterized by DTA/TG, x-ray diffraction, field-emission scanning electron microscope, transmission electron microscope, and UV-Vis-NIR, respectively. The results show the presence of rutile (~15 nm) and anatase phases (~17 nm) in as-synthesized TiO2 nanoparticles. TiO2 nanoparticles are heat treated for 2 h at 200, 400, and 600 °C in air. It is observed that heat treatment results in higher photoactivity in visible region of the solar radiation and the material demonstrated high photovoltaic performance in conjunction with N-719. The optical band gap values are found to be in the range of 2.59-2.88 eV. The dye-sensitized solar cells (DSSCs) fabricated by TiO2 nanoparticles, heat treated at 600 °C show the energy conversion efficiency (η) of 6.08% with high photo current density (Jsc) of 11.76 mA/cm2. The work highlighted in this paper represents the realization of simple method of achieving low band gap semiconductors without being doped, for DSSCs applications.

Energy, Énergie, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Combustibles, Fuels, Combustibles nucléaires, Nuclear fuels, Préparation et traitement des combustibles nucléaires, Preparation and processing of nuclear fuels, Pollution, Déchets, Wastes, Déchets radioactifs, and Radioactive wastes

In order to simulate high-burnup fuel cladding degradation under various interim dry storage conditions, 250 ppm and 500 ppm hydrogen-charged Zr-Nb alloy cladding tubes were used to investigate the effect of terminal cool-down temperature on hydride reorientations and subsequent mechanical property degradations under a tensile hoop stress of 150 MPa with two cooling rates of 2.0 and 7.0 °C/min from a peak temperature of 400 °C to three respective terminal cool-down temperatures of 300, 200 and 25 °C. The cool-down tests showed that the slower cooling rate, the lower terminal cool-down temperature and the higher hydrogen content generated the larger fraction of radial hydrides precipitated during the cool-down. This may be explained by hydrogen solid solubilities for precipitation at the respective terminal cool-down temperatures, by cooling rate-dependent residence times at a relatively high temperature during the cool-down and by remaining circumferential hydrides prior to the cool-down. Ultimate tensile strengths, plastic strains and fracture modes for the tensile-tested specimens are found to be well correlated to the amount of the radial and circumferential hydrides and hydride morphologies.

Energy, Énergie, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Installations de production et de conversion d'énergie: énergie électrique, énergie thermique., Installations for energy generation and conversion: thermal and electrical energy., Centrales nucléaires à fission, and Fission nuclear power plants

Tensile stress-strain relationship of a rolled Zircaloy-4 (Zr-4) plate was examined in situ using a neutron diffraction method at room temperature (RT, 25 °C) and an elevated temperature (250 °C). Variations of lattice strains were obtained as a function of macroscopic bulk strains along prismatic (1010), basal (0002) and pyramidal (1011) planes in the hexagonal close-packed structure of the Zr-4. The mechanisms of strain responses in these three major planes were simulated using elastic-plastic self-consistent (EPSC) model based on Hill-Hutchinson method, thus the inter-granular stresses and deformation systems of each individual grain under loading were obtained. Results show that there is a good agreement between the EPSC modeling and neutron diffraction measurements in terms of macroscopic stress-strain relationship and lattice strain evolutions of the planes at RT. However, there is a slight discrepancy in the lattice strains obtained from the EPSC modeling and neutron diffraction when the specimen was deformed at 250 °C. Analysis of grain structure and texture obtained using electron back-scattered diffraction suggests that dynamic recovery process is significant during the tensile deformation at the elevated temperature, which was not considered in the simulation.

Energy, Énergie, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Matériaux particuliers, Specific materials, Métaux, semimétaux et alliages, Metals, semimetals and alloys, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Installations de production et de conversion d'énergie: énergie électrique, énergie thermique., Installations for energy generation and conversion: thermal and electrical energy., Centrales nucléaires à fission, and Fission nuclear power plants

The nanoparticles in an Al-alloyed high-Cr oxide dispersion strengthened (ODS) steel with Zr addition, i.e., SOC-14 (Fe-15Cr-2W-0.1Ti-4Al-0.63Zr-0.35Y2O3), have been examined by transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). Relative to an Al-alloyed high-Cr oxide ODS steel without Zr addition, i.e., SOC-9 (Fe-15.5Cr-2W-0.1Ti-4Al-0.35Y2O3), the dispersion morphology and coherency of the oxide nanoparticles in SOC-14 were significantly improved. Almost all the small nanoparticles (diameter <10 nm) in SOC-14 were found to be consistent with trigonal δ-phase Y4Zr3O12 oxides and coherent with the bcc steel matrix, with semi-coherent ortho-rhombic Y2TiO5 oxides occasionally detected. The large particles were mainly identified as tetragonal or cubic ZrO2 oxide. The results are compared with those of SOC-9 with a brief discussion of the mechanisms of the unusual thermal and irradiation stabilities of the oxides as well as the extraordinary corrosion resistance, excellent irradiation tolerance and superior strength of SOC-14.

Inorganic chemistry, Chimie minérale, Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Combustibles, Fuels, Combustibles de remplacement. Production et utilisation, Alternative fuels. Production and utilization, Hydrogène, Hydrogen, Adsorption, Adsorción, Diffraction RX, X ray diffraction, Difracción RX, Enthalpie, Enthalpy, Entalpía, Microsphère, Microsphere, Microsfera, Polymère coordination, Polychelate, Polímero coordinación, Relation ordre, Ordering, Relación orden, Stockage hydrogène, Hydrogen storage, Synthèse solvothermale, Solvothermal synthesis, Síntesis solvotermal, Adsorption enthalpy, Coordination polymer microspheres, Hydrogen uptake capacity, and Metal ions

In this paper, three coordination polymer microspheres based on different metal ions have been fabricated via solvothermal method by using 1,1'-ferrocenedicarboxylic acid as organic linker. The as-synthesized samples are of high local crystalline ordering, as confirmed by powder X-ray diffraction patterns. These materials cannot only remain stable up to nearly 400°C, but also have improved hydrogen storage capacity, reaching 1.60 wt%, 2.12 wt% and 1.22 wt% at 163 K, 5 MPa. The influence of metal ions on hydrogen uptake capacity has investigated and the corresponding adsorption enthalpy has been calculated. The comparison between these three microspheres indicates that the impact of metal ions follows the trend of Zn2+ < Mn2+ < Co2+, which is a useful conclusion for future material design.

Inorganic chemistry, Chimie minérale, Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Combustibles, Fuels, Combustibles de remplacement. Production et utilisation, Alternative fuels. Production and utilization, Hydrogène, Hydrogen, Cobalt Sulfophosphure, Cobalt Phosphides sulfides, Cobalto Fosfuro sulfuro, Diffraction RX, X ray diffraction, Difracción RX, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Microstructure, Microestructura, Nickel Thiophosphate, Nickel Thiophosphates, Niquel Tiofosfato, Réaction état solide, Solid state reaction, Reacción estado sólido, Stabilité thermique, Thermal stability, Estabilidad térmica, Stockage hydrogène, Hydrogen storage, Traitement thermique, Heat treatment, Tratamiento térmico, Cobalt phosphide sulfide, and Nickel phosphorous trisulfide

Prepared CoPS and NiPS3 are studied as new materials for hydrogen energy storage. Single phase of CoPS and NiPS3 were grown separately in evacuated silicatube via solid state reaction at 650 °C with controlled heating rate 1 °C/min. X-ray diffraction patterns confirm the formation of the desired compounds. Both CoPS and NiPS3 exhibited high thermal stability up to 700 °C and 630 °C, respectively. The morphology of the prepared samples was investigated using scanning electron microscopy and folded sheets appeared in the transmission electron microscopy. The samples were exposed to 20 bar applied hydrogen pressure at 80 K. Both compounds appear to have feasible hydrogen storage capacity. CoPS was capable to adsorb 1.7 wt% while NiPS3 storage capacity reached 1.2 wt%.

Crystallography, Cristallographie cristallogenèse, Electronics, Electronique, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Nanomatériaux et nanostructures : fabrication et caractèrisation, Nanoscale materials and structures: fabrication and characterization, Points quantiques, Quantum dots, Divers, Other topics in nanoscale materials and structures, Méthodes de nanofabrication, Methods of nanofabrication, Sciences appliquees, Applied sciences, Energie, Energy, Energie naturelle, Natural energy, Energie solaire, Solar energy, Conversion photovoltaïque, Photovoltaic conversion, Cellules solaires. Cellules photoélectrochimiques, Solar cells. Photoelectrochemical cells, Bande interdite, Energy gap, Cellule solaire, Solar cells, Epaisseur, Thickness, Nanomatériau, Nanostructured materials, Nanoparticule, Nanoparticles, Photoélectrode, Photoelectrode, Fotoelectrodo, Phénomène transport, Transport processes, Point quantique, Quantum dots, Propriété électronique, Electronic properties, Propiedad electrónica, Synthèse nanomatériau, Nanomaterial synthesis, Síntesis nanomaterial, Synthèse solvothermale, Solvothermal synthesis, Síntesis solvotermal, 8107T, 8460J, CdS, Cu2ZnSnS4, CZTS, QD, counter electrodes, and solar cells

Cu2ZnSnS4 (CZTS) nanoparticles have been synthesized through a one-step solvothermal route, which exhibited a nearly single kesterite structure with a fundamental band gap of ~1.54 eV. Quantum dots-sensitized solar cells were fabricated based on CZTS counter electrodes and CdS QD-sensitized TiO2 NRs photoelectrodes with various thicknesses of QD sensitization layers. The cells based on a CZTS electrode, compared with other single-layer DSSCs in this study, had the highest conversion efficiency of 0.27% (for CdS layer numbers of 9), which was obviously higher than Pt. The performance improvement was attributed to the better stability, sunlight sensitivity, and the resulting photoelectrocatalytic activity of the CZTS electrodes.

Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Electrochimie, Electrochemistry, Electrodes: préparations et propriétés, Electrodes: preparations and properties, Sciences appliquees, Applied sciences, Energie, Energy, Energie naturelle, Natural energy, Energie solaire, Solar energy, Conversion photovoltaïque, Photovoltaic conversion, Cellules solaires. Cellules photoélectrochimiques, Solar cells. Photoelectrochemical cells, Bande interdite, Energy gap, Banda prohibida, Cellule solaire, Solar cell, Célula solar, Copolymère, Copolymer, Copolímero, Couche mince, Thin film, Capa fina, Dispositif photovoltaïque, Photovoltaic cell, Dispositivo fotovoltaico, Hétérojonction, Heterojunction, Heterounión, Polymère conjugué, Conjugated polymer, Polímero conjugado, Propriété électrochimique, Electrochemical properties, Propiedad electroquímica, Spectre absorption, Absorption spectrum, Espectro de absorción, 8245F, 8245M, 8460J, Benzodithiophene, Conjugated polymers, Polymer solar cells, and Thiadiazole

Two copolymers comprised of different fused thiadiazole electron withdrawing units and benzo[1,2-b:4,5-b'] dithiophene electron donating unit have been synthesized by Stille reaction. The structural, optical, electrochemical and photovoltaic properties of the copolymers were investigated. Both copolymers in the film state exhibited abroad absorption spectra with an extremely low bandgap of ∼1.2 eV. Bulk heterojunction solar cells were further fabricated and the best device delivered a power conversion efficiency of 0.52% when thermal annealed at 90 °C.

Inorganic chemistry, Chimie minérale, Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Combustibles, Fuels, Combustibles de remplacement. Production et utilisation, Alternative fuels. Production and utilization, Hydrogène, Hydrogen, Calorimétrie différentielle balayage, Differential scanning calorimetry, Análisis calorimétrico barrido exploración, Diffraction RX, X ray diffraction, Difracción RX, Haute pression, High pressure, Alta presión, Hydrure de magnésium, Magnesium hydride, Magnesio hidruro, Hydrure de scandium, Scandium hydride, Escandio hidruro, Méthode Rietveld, Rietveld method, Método Rietveld, Processus réversible, Reversible processes, Rayonnement synchrotron, Synchrotron radiation, Radiación sincrotrón, Réseau cubique face centrée, FCC lattices, Stockage hydrogène, Hydrogen storage, Hydrogen, Magnesium, Metal hydride, and Scandium

A face centered cubic (FCC) type Mg-Sc hydride (Mg0.8Sc0.2HX phase) was prepared by an ultra-high pressure (UHP) technique generating an 8 GPa hydrogen pressure. Reversible hydrogen releasing and restoring behaviors have been observed by a differential scanning calorimeter (DSC) measurement at a 0.5 MPa hydrogen pressure. The hydrogen releasing temperature was lower by around 70 K than that of MgH2. The structural analysis using a Rietveld refinement of the synchrotron X-ray diffraction patterns indicated that the FCC phase was preserved without decomposition after the reproducible hydrogen releasing and restoring reactions.

Energy, Énergie, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industries chimique et parachimique, Chemical industry and chemicals, Matériaux de construction. Céramique. Verres, Building materials. Ceramics. Glasses, Industries céramiques, Ceramic industries, Céramiques techniques, Technical ceramics, Etudes générales, and General studies

U-doped sphene ceramics with and without Al as charge compensation, i.e. Ca1-xUxTi1-2xAl2xSiO5 and Ca1-2yUyTiSiO5, were prepared by solid-state reaction method. The effects of U content on the phase structure of the ceramics were investigated. The chemical durability of U-doped sphene ceramic waste forms was also examined. The results show that the optimum sintering temperature of the U-doped sphene ceramics is about 1260°C. For the ceramics with x ≤ 0.065 or y ≤ 0.045, the primary crystalline phase is sphene, and a small amount of CaTiO3, SiO2 phases are also oberved. UO2 phase appears when x ≥ 0.07 or y ≥ 0.05. The solubility of U in Ca1-2yUyTiSiO5 is lower than that in the samples with Al as charge compensation. Moreover, the normalized elementary release rate of U in both the Ca1-xUxTi1-2x-Al2xSiO5 and Ca1-2yUyTiSiO5 ceramics decreases with increasing time and remains almost unchanged (~2 x 10-3 g m-2 d-1) after 28 days, exhibiting high chemical durability. These results suggest that the sphene-based ceramics are promising candidate for the immobilization of actinides.

Energy, Énergie, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Structure des liquides et des solides; cristallographie, and Structure of solids and liquids; crystallography

Gadolinium (Gd3+) was used to simulate trivalent minor actinide curium (Cm3+), and monazite-type solid solutions with composition of Ce1-xGdxPO4 (x= 0―1) were prepared by the solid state reaction method using Ce2(C2O4)3·10H2O, NH4H2PO4, and Gd2O3 as starting materials. The effects of Gd content on the crystalline phase and microstructure of Ce1―xGdxPO4 solid solutions were investigated, and the calcining parameters of Ce0.9Gd0.1PO4 solid solution were optimized by means of XRD, TG-DSC and SEM. The results show that pure monazite-type crystalline phase was obtained for the Ce1―xGdxPO4 with x = 0-1, and the incorporation of minor actinide curium simulated by gadolinium in monazite was confirmed. The change of Gd content had no significant effect on the microstructure of Ce1―xGdxPO4 solid solutions, and the grain size was approximately 0.1-1 μm. Besides, the optimal calcining temperature and holding time of Ce0.9-Cd0.1PO4 solid solution were 1000 °C and 2 h, respectively.

Energy, Énergie, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Pollution, Déchets, Wastes, Déchets radioactifs, and Radioactive wastes

Zirconolite and monazite matrices are potential ceramics for the containment of actinides (Np, Cm, Am, Pu) which are produced over the reprocessing of spent nuclear fuel. Actinides decay mainly through the emission of alpha particles, which in turn causes most ceramics to undergo structural and textural changes (amorphization and/or swelling). In order to study the effects of alpha decays on the above mentioned ceramics two parallel approaches were set up. The first involved the use of an external irradiation source, Au, which allowed the deposited recoil energy to be simulated. The second was based on short-lived actinide doping with 238Pu, (i.e. an internal source), via the incorporation of plutonium oxide into both the monazite and zirconolite structures during synthesis. In both types of irradiation experiments, the zirconolite samples became amorphous at room temperature with damage close to 0.3 dpa; corresponding to a critical dose of 4 × 1018 α g-1 (i.e. ~1.3 × 1021 keV cm-3). Both zirconolite samples also showed the same degree of macroscopic swelling at saturation (~6%), with ballistic processes being the predominant damaging effect. In the case of the monazite however, the macroscopic swelling and amorphization were dependent on the nature of the irradiation. Externally, (Au), irradiated samples became amorphous while also demonstrating a saturation swelling of up to 8%. In contrast to this, the swelling of the 238Pu doped samples was much smaller at ~1%. Also, unlike the externally (Au) irradiated monazite these 238Pu doped samples remained crystalline up to 7.5 × 1018 α g-1 (0.8 dpa). XRD, TEM and swelling measurements were used to fully characterize and interpret this behavior. The low swelling and the conservation of the crystalline state of 238Pu doped monazite samples indicates that alpha annealing took place within this material.

Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Surfaces et interfaces; couches minces et trichites (structure et propriétés non électroniques), Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties), Propriétés physiques non électroniques de couches minces, Physical properties of thin films, nonelectronic, Stabilité thermique; effets thermiques, Thermal stability; thermal effects, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Nanomatériaux et nanostructures : fabrication et caractèrisation, Nanoscale materials and structures: fabrication and characterization, Divers, Other topics in nanoscale materials and structures, Méthodes de nanofabrication, Methods of nanofabrication, Sciences appliquees, Applied sciences, Energie, Energy, Energie naturelle, Natural energy, Energie solaire, Solar energy, Conversion photovoltaïque, Photovoltaic conversion, Cellules solaires. Cellules photoélectrochimiques, Solar cells. Photoelectrochemical cells, Chaîne longue, Long chain, Cadena larga, Conversion énergie, Energy conversion, Couche mince, Thin films, Diffraction RX, XRD, Dispositif photovoltaïque, Photovoltaic cell, Dispositivo fotovoltaico, Défaut surface, Surface defect, Defecto superficie, Fer, Iron, Ligand, Ligands, Nanocristal, Nanocrystal, Nanomatériau, Nanostructured materials, Oxydation, Oxidation, Propriété thermique, Thermal properties, Pyridine, Pyrite, Recuit thermique, Thermal annealing, Recocido térmico, Réseau cubique, Cubic lattices, Spectrométrie Raman, Raman spectroscopy, Spectrométrie transformée Fourier, Fourier transform spectroscopy, Stabilité thermique, Thermal stability, Synthèse nanomatériau, Nanomaterial synthesis, Síntesis nanomaterial, Trioctylphosphine oxyde, TOPO, 6860D, 8460J, FeS2, FeS2 nanocrystals, Iron pyrite, Ligand exchange, Photovoltaic, and Surface stability

Iron pyrite (FeS2) is a promising photovoltaic absorber material with a high natural abundance and low cost, but surface defects and low photoresponse inhibit sunlight energy conversion. The surface stability of pyrite FeS2 nanocrystals synthesized in oleylamine (OLA) with trioctylphosphine oxide (TOPO) as an additional capping ligand was investigated using Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray diffraction. Tunable laser exposure during Raman spectroscopy measurement was developed for convenient and systematic evaluation of the stability of FeS2 nanocrystals. The surface stability of 100―200 nm diameter cubic nanocrystals with long-chain (OLA, TOPO) or small-molecule (pyridine) capping ligands was evaluated after high-intensity laser exposure as well as after thermal annealing in air and N2. While increasing surface coverage with OLA and TOPO capping ligands provided additional protection against oxidation, FeS2 nanocrystals capped with pyridine showed good stability at temperatures up to 200 °C in air and 400 °C in N2. These results provide greater understanding of the processing of nanocrystal-based iron pyrite thin films for photovoltaic applications.

Energy, Énergie, Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Installations de production et de conversion d'énergie: énergie électrique, énergie thermique., Installations for energy generation and conversion: thermal and electrical energy., Centrales nucléaires à fission, and Fission nuclear power plants

Zr-Si alloys were designed to contain eutectic phase surrounding the parent phase to suppress creep behavior of claddings. Creep tests conducted at 294-573 K showed that creep behavior was inhibited and that the creep failure time of new Zr alloy became longer than that of a conventional alloy: Zircaloy-4. Results show that the eutectic phase can suppress creep at operating temperatures prevailing in current nuclear power plants.

Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie naturelle, Natural energy, Energie solaire, Solar energy, Conversion photovoltaïque, Photovoltaic conversion, Cellules solaires. Cellules photoélectrochimiques, Solar cells. Photoelectrochemical cells, Addition fluor, Fluorine addition, Adición fluor, Addition étain, Tin addition, Adición estaño, Cellule solaire, Solar cell, Célula solar, Couche mince, Thin film, Capa fina, Diffusion lumière, Light scattering, Difusión luz, Dispositif photovoltaïque, Photovoltaic cell, Dispositivo fotovoltaico, Pyrolyse, Pyrolysis, Pirólisis, Silicium, Silicon, Silicio, Verre, Glass, Vidrio, 8460J, Couche mince amorphe hydrogénée, SnO2, Substrat verre, a-Si:H, μc-Si:H, Current matching, Flexible glass, Superstrate type, Thin-film Si solar cell, and Transparent front electrode

We have investigated the flexible thin-film silicon (Si) solar cells fabricated on the flexible glass substrates. The preliminary p-i-n type flexible hydrogenated amorphous silicon (a-Si:H)/hydrogenated microcrystalline silicon (μc-Si:H) double-junction solar cell is compared with its counterpart fabricated on the textured F-doped tin oxide-coated glass substrate. Because of the inferior light transmitting and scattering of the SnO2:F front electrode coated by a spray pyrolysis deposition in the long wavelength region, the preliminary flexible solar cell shows a severely limited short-circuit current. Without any back reflector, the initial efficiency of 8.0% and stabilized efficiency of 7.1% are achieved. The initial efficiency of 9.3% was achieved by improving the current matching. The superstrate type thin-film Si photovoltaic technology using flexible transparent substrates has a high potential to minimize the cell-to-module loss through a monolithic series integration using a laser scribe technique.

Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Structure électronique et propriétés électriques des surfaces, interfaces, couches minces et structures de basse dimensionnalité, Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures, Phénomènes de transport électronique dans les couches minces et les structures de basse dimensionnalité, Electronic transport phenomena in thin films and low-dimensional structures, Propriétés optiques, spectroscopie et autres interactions de la matière condensée avec les particules et le rayonnement, Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation, Propriétés optiques des couches minces, Optical properties of specific thin films, Propriétés optiques des structures de basse dimensionnalité, mésoscopiques, des nanostructures et nanomatériaux, Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures, Sciences appliquees, Applied sciences, Energie, Energy, Energie naturelle, Natural energy, Energie solaire, Solar energy, Conversion photovoltaïque, Photovoltaic conversion, Cellules solaires. Cellules photoélectrochimiques, Solar cells. Photoelectrochemical cells, Cellule solaire, Solar cells, Conductivité type p, P type conductivity, Conductividad tipo p, Couche mince, Thin films, Dispositif photovoltaïque, Photovoltaic cell, Dispositivo fotovoltaico, Dépôt projection, Spray coatings, Film polymère, Polymer films, Grosseur grain, Grain size, Hétérojonction, Heterojunctions, Matériau poreux, Porous materials, Mésoporosité, Mesoporosity, Mesoporosidad, Optimisation, Optimization, Propriété optique, Optical properties, Propriété électrique, Electrical properties, Solvant organique, Organic solvents, Thiophène dérivé polymère, Thiophene derivative polymer, Tiofeno derivado polímero, Titane, Titanium, 8460J, Substrat métal, Substrat polymère, Hybrid solar cells, Spray coating, Titanium dioxide, and Water-soluble poly(3-hexylthiophene)

Solid-state hybrid solar cells are promising candidates for future low-cost photovoltaic energy generation that are based on polymer/metal oxide donor/acceptor heterojunctions. However, a critical drawback of hybrid solar cells is the usage of toxic and environmental unfriendly organic solvents in the phase of preparation. In terms of environmental impact, green and safer materials are required towards processing of eco-friendly hybrid solar cells. In this work, during processing phase of eco-friendly hybrid solar cells, aqueous-soluble conjugated poly(3-hexylthiophene) material is used as photo-active and hole transporting layer and TiO2 layer as electron accepting layer. Optical, topographical and morphological characterizations on different grain-sized TiO2 layers with polymer films are studied. The influence of eco-friendly hybrid solar cell electrical properties in combination with different grain-sized TiO2 layers measured under N2 and ambient conditions are discussed. It is important to understand these properties for further optimizations.